1. Field of the Invention
The present invention relates generally to cameras and, more specifically, to video camera pan tilt mechanisms.
2. Description of the Related Art
Video conferencing systems may use cameras to capture images of conference participants at one site to transmit and display to conference participants at another site. While high definition (HD) cameras may be used to provide high definition images, they may be too large and too difficult to control for a video conferencing system. For example, it may not be possible to place a HD camera on top of a computer monitor as part of a conference system.
Traditionally, a tilt motor on the HD camera may be used in a rotating head of the HD camera structure and coupled to a lens/sensor assembly on the HD camera. A panning mechanism on the HD camera may need to overcome inertia of not only the lens/sensor assembly, but also the inertia of the tilt motor and linkage in the rotating head of the HD camera. In addition, traditional HD cameras may use thick cables to send analog signals (which may be susceptible to noise).
Video conferencing systems have traditionally been of the set-top box format. Examples are the Polycom ViewStation and Tandberg 880. These may be in the range of 13-17″ wide by 8-10″ deep and 6-10″ high. They may be placed on the top of cathode ray tube (CRT) based televisions so the camera is above the display device showing the remote participants during a video call.
As large screen (32″-65″) HiDef televisions have become more popular, the television industry has been transitioning away from CRT based devices and moving toward plasma and liquid crystal displays (LCD) screens, which allow the display to be much thinner. Current plasma and LCD televisions may be as thin as 3-4″. This means the display may no longer have a set-top on which to place a video conferencing system. The camera of a video conferencing system may need to be as close to the display as possible in order optimize eye contact. However, displays may not be thick enough or flat enough to hold traditional set-top box video conferencing systems.
The top surfaces of the displays may also not have a consistent shape or depth making it very difficult to place a camera on top of the display without it being very unstable and likely to fall off. One solution is to install a shelf above the monitor and place the camera on the shelf. However, that may mean the system cannot be moved around and may need to be permanently installed close to a wall (needed to mount the shelf).